Gastrointestinal nematodes of the Isla Cerralvo Spiny Lizard, Sceloporus grandaevus (Phrynosomatidae) from Baja California Sur, Mexico.
The Isla Cerralvo Spiny Lizard, Sceloporus grandaevus is endemic to Isla Cerralvo (24[degrees]30'N, 109[degrees]40'W), Baja California Sur, Mexico. It commonly occurs in rocky arroyos, avoiding areas devoid of vegetation (Grismer 2002). To our knowledge, helminths have not been reported from S. grandaevus. We herein report two nematode species from S. grandaevus.Twenty Sceloporus grandaevus (mean Snout-vent length, 61.1 mm [+ or -] 8.9 SD, range = 50-78 mm) collected July 1960 on the southwest portion of Isla Cerralvo were examined (Appendix). Lizards were fixed originally in 10% formalin and preserved in 70% ethanol. The body cavity had been opened by previous investigators; however, the internal organs were intact. The digestive tract was removed, opened longitudinally and the esophagus, stomach, small and large intestines were searched for helminths using a dissecting microscope. Only nematodes were found. These were placed on microscope slides and allowed to clear in a drop of undiluted glycerol. A coverslip was added and the nematodes were identified with a compound microscope.
Two species of Nematoda, Atractis penneri (Gambino, 1957) and Thubunaea iguanae Telford, 1965 were found. Selected specimens were placed in vials of 70% ethanol and deposited in the United States National Parasite Collection, (USNPC), Beltsville, Maryland: Atractis penneri USNPC 92115; Thubunaea iguanae USNPC 92116. Number of individuals, prevalence (percentage of infected lizards), mean intensity [+ or -] 1 SD (mean number of helminths per infected host) range and infection site, respectively, for each neamtode species are: Atractis penneri, 1,216, 20% 304 [+ or -] 239 SD, 35-525, large intestine; Thubunaea iguanae, 6, 25% 1 [+ or -] 0.4 SD, 1-2, stomach, small intestine.
Atractis penneri is widespread and has been reported in lizards of the genera Callisaurus, Crotaphytus, Gambelia, Holbrookia, Phrynosoma, Sceloporus, Uma and Uta occurring from the western United States, northern Mexico and Baja California (Baker 1987).
Thubunaea iguanae was described by Telford (1965) from the stomachs of lizards collected in California and Mexico. He reported its occurrence from Isla San Esteban in the Gulf of California but the lizard host was not given. Thubunaea iguanae is primarily known from California wehre it has been reported from Callisaurus, Cnemidophorus, Crotaphytus, Sceloporus, Uma, Uta and Xantusia (Baker 1987).
Sceloporus grandaevus is a new host record for Atractis penneri and Thubunaea iguanae and Isla Cerralvo is a new locality for both nematode species. A list of lizards from Baja California found to harbor A. penneri and T. iguanae is presented in Table 1.
Appendix
Specimens of Sceloporus grandaevus examined from the herpetology collection of the Natural History Museum of Los Angeles County (LACM): 9935, 9940, 9942, 9948, 9956, 9963-9966, 9970, 9972, 9977, 9979, 36481-36483, 36486, 36487, 36496, 36500.
Table 1 Reports of Atractis penneri and Thubunaea iguanae in lizards from Baja California, Mexico. Nematode Lizard host Locality Prevalence Atractis penneri Callisaurus Isla Angel de la Guarda 5/12, 42% draconoides Bahia San Francisquito 2/2, 100% not given 13/34, 38% Gambelia not given 1/1, 100% wislizenii Petrosaurus sp. not given 1/1, 100% Sceloporus Isla Cerralvo 4/20, 20% grandaevus Sceloporus not given 1/1, 100% magister Thubunaea iguanae Sceloporus Isla Cerralvo 5/20, 25% grandaevus Unidentified not given not stated lizard(s) Nematode Lizard host Reference Atractis penneri Callisaurus Gambino and Heynemann 1960 draconoides Gambino and Heynemann 1960 Gambino and Heynemann 1960 Gambelia Gambino and Heynemana 1960 wislizenii Petrosaurus sp. Gambino and Heynemann 1960 Sceloporus this study grandaevus Sceloporus Gambino and Heynemann 1960 magister Thubunaea iguanae Sceloporus this study grandaevus Unidentified Telford 1965 lizard(s)
Acknowledgments
We thank David A. Kizirian (Natural History Museum of Los Angeles County) for permission to examine the museum specimens of S. grandaevus.
Accepted for publication 26 June 2002.
Literature Cited
Baker, M. R. 1987. A synopsis of the Nematoda parasitic in amphibians and reptiles. Memorial Univ, Newfoundland, Occas. Pap. Biol., 11:1-325.
Gambino, J. J. and D. Heyneman. 1960. Specificity and speciation in the genus Cyrtosomum (Nematoda: Atractidae). Am. Midl. Nat., 63:365-382.
Grismer, L. L. 2002. Amphibians and reptiles of Baja California, including its Pacific islands and the islands in the Sea of Cortes. Univ. Calif. Press, Berkeley, 409 pp.
Telford, S. R., Jr. 1965. A new species of Thubunae (Nematoda: Spiruroidea) from California lizards. Jap. J. Exp. Med., 35:111-114.
Stephen R. Goldberg, (1) Charles R. Bursey, (2) and Kent R. Beaman (3)
(1.) Department of Biology, Whittier College, Whittier, California 90608 e-mail: sgoldberg@whittier.edu
(2.) Department of Biology, Pennsylvania State University, Shenango Campus, Sharon, Pennsylvania 16146 email: cxb13@psu.edu
(3.) Section of Herpetology, Natural History Museum of Los Angeles County, 900 Exposition Bouldevard, Los Angeles, California 90007 e-mail: kbeaman@nhm.org
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| Author: | Goldberg, Stephen R.; Bursey, Charles R.; Beaman, Kent R. |
|---|---|
| Publication: | Bulletin (Southern California Academy of Sciences) |
| Geographic Code: | 1MEX |
| Date: | Dec 1, 2002 |
| Words: | 767 |
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